Impact of resuscitation strategies on the acetylation status of cardiac histones in a swine model of hemorrhage
Impact of resuscitation strategies on the acetylation status of cardiac histones in a swine model of hemorrhage
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DOI：
10.1016/j.resuscitation.2007.07.030
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发表时间：
2008-02-01
期刊：
影响因子：
6.5
通讯作者：
Velmahos, George C.
中科院分区：
文献类型：
--
作者：
Alam, Hasan B.;Shults, Christian;Velmahos, George C.
背景：组蛋白乙酰化导致的染色质重构是基因转录的关键调控机制。我们以前已经表明，啮齿动物的液体复苏与心脏组蛋白的高度结构化的翻译后修饰相结合。目前的实验是为了在出血和复苏的临床相关大型动物模型中验证这一概念，并将组蛋白乙酰化的变化与立即早期反应基因的表达改变相关联。约克郡猪（n=49，7/组，体重=40- 58 kg）同时接受未控制和控制出血（估计血容量的40%），并随机分配至以下复苏组：（1）0.9%盐水（NS），（2）外消旋乳酸林格氏液（DL-LR），（3）L-异构体乳酸林格氏液（L-LR），（4）酮林格氏液（KR），（5）6%羟乙基淀粉的盐水溶液（Hespan）。KR含有乳酸与β-羟基丁酸的等摩尔取代。无出血（NH）和无复苏（NR）组作为对照。采用Western blotting方法检测心肌蛋白的总乙酰化和组蛋白乙酰化。进一步评估组蛋白亚基H3和H4的赖氨酸残基特异性乙酰化。此外，使用染色质免疫沉淀（ChIP）技术分离与乙酰化组蛋白（H3和H4亚基）结合的DNA，然后测量因出血/复苏而改变的基因，包括立即早期反应基因（c-fos和c-myc）和热休克蛋白（HSP）70。结果：复苏所用液体的类型影响心脏组蛋白乙酰化的模式。用DL-LR和KR复苏诱导H3 K9上的超乙酰化。KR复苏还与H3 K14和H4 K5上乙酰化增加以及H3 K18上乙酰化不足相关。基因的表达也是液体特异性的，在KR复苏后变化最多（c-fos和c-myc增加，HSP 70与H3相关; c-myc增加与H4相关）。在所研究的组蛋白亚基中，改变的H3乙酰化与大多数即刻早期基因表达的变化相关。结论：心脏组蛋白的乙酰化状态受出血的影响，通过复苏进一步调节，产生在不同物种中保存的液体特异性代码。用KR复苏导致组蛋白在最大数量的赖氨酸位点（主要是H3亚基）乙酰化，并且对所选（立即早期反应）基因的转录调控具有最显著的影响。(c)2007爱思唯尔爱尔兰有限公司保留所有权利。
Background: Chromatin remodeling through histone acetylation is a key control mechanism in gene transcription. We have shown previously that fluid resuscitation in rodents is coupled with highly structured post-translational modifications of cardiac histones. The current experiment was performed to validate this concept in a clinically relevant large animal model of hemorrhage and resuscitation, and to correlate the changes in histone acetylation with altered expression of immediate-early response genes.Study design: Yorkshire swine (n=49, 7/group, weight=40-58kg) were subjected to combined uncontrolled and controlled hemorrhage (40% of estimated blood volume) and randomly assigned to the following resuscitation groups: (1) 0.9% saline (NS), (2) racemic lactated Ringer's (DL-LR), (3) L-isomer lactated Ringer's (L-LR), (4) Ketone Ringer's (KR), (5) 6% hetastarch in saline (Hespan). KR contained an equimolar substitution of lactate with beta-hydroxybutyrate. No hemorrhage (NH) and no resuscitation (NR) groups were included as controls. Cardiac protein was used in Western blotting to analyze total protein acetylation and histone acetylation specifically. Lysine residue-specific acetylation of histone subunits H3 and H4 was further evaluated. In addition, Chromatin Immunoprecipitation (ChIP) technique was used to separate the DNA bound to acetylated histones (H3 and H4 subunits), followed by measurement of genes that are altered by hemorrhage/resuscitation, including immediate-early response genes (c-fos and c-myc), and heat shock protein (HSP) 70. Results: The type of fluid used for resuscitation influenced the patterns of cardiac histone acetylation. Resuscitation with DL-LR and KR induced hyperacetylation on H3K9. KR resuscitation was also associated with increased acetylation on H3K14 and H4K5, and hypoacetylation on H3K18. The expression of genes was also fluid specific, with the largest number of changes following KR resuscitation (increased c-fos and c-myc, HSP 70 linked with H3; and increased c-myc Linked with H4). Among the histone subunits studied, altered H3 acetylations were associated with the majority of changes in immediate-early gene expression. Conclusions: Acetylation status of cardiac histones, affected by hemorrhage, is further modulated by resuscitation producing a fluid-specific code that is preserved in different species. Resuscitation with KR causes histone acetylation at the largest number of Lysine sites (predominately H3 subunit), and has the most pronounced impact on the transcriptional regulation of selected (immediate-early response) genes. (c) 2007 Elsevier Ireland Ltd. ALL rights reserved.